The Electrical System and Electric Service

Which component is part of a building’s electrical system and is used to measure electricity consumption?

• Service panel

• Meter

• Receptacle

• Switch

Electricity is supplied to a typical building via a service drop that includes three wires. What is the role of the third wire?

• It carries 240V continuously

• It synchronizes the two hot wires

• It is the neutral or ground at zero volts

• It converts AC to DC

A clothes dryer requires 240V. Using the information about opposite AC voltages, which connection provides 240V?

• One hot wire to neutral (120V − 0V)

• Two neutrals (0V − 0V)

• Between the two hot wires (120V − (−120V))

• Hot wire to ground (120V − 0V)

Which statement best defines electric power as presented?

• The total amount of energy stored in a device

• The rate at which energy is used

• The maximum voltage a circuit can handle

• The cost charged by the utility company

What is the standard unit used to measure electric power?

• Volts

• Amperes

• Watts

• Ohms

In a building’s main electrical panel, what is the purpose of the main breaker compared with the smaller circuit breakers?

• The main breaker measures energy use; smaller breakers distribute power.

• The main breaker distributes power; smaller breakers measure current.

• The main breaker allows all power to be switched off; smaller breakers allow individual circuits to be switched off.

• The main breaker increases voltage; smaller breakers decrease voltage.

In standard building wiring, which color typically identifies the hot wire inside a sheathed cable?

• Black

• White

• Green

• Blue

On a standard receptacle, which feature correctly matches the prong pattern?

• Hot slot is longer than the neutral slot

• Neutral slot is longer than the hot slot

• Grounding socket is rectangular

• Both slots are the same length by code

Which statement best describes the function of a receptacle?

• It converts AC to DC for devices.

• It is an outlet that connects devices to power and continues the circuit through hot, neutral, and ground wires in the cord.

• It only provides a ground connection for safety.

• It measures current flow in a circuit.

Where are Ground-Fault Circuit Interrupters (GFCIs) required by code due to potential exposure to water?

• Bedroom and hallway

• Garage and attic

• Kitchen and bathroom

• Living room and dining room